The present invention generally relates to booted stirrups for holding a person's leg during surgery, and more specifically, to a ratchet mechanism for a booted stirrup.
Surgical stirrups typically include a boot which holds a foot of a person during surgery to orient and/or position the person's leg. The stirrups also typically include a support arm attached to the operating room table which supports the boot. The support arm of some stirrups rotate by means of a ratchet mechanism to different fixed angular positions. For example, see U.S. Pat. No. 5,560,577 and U.S. patent application Ser. No. 08/412,148, now U.S. Pat. No. 5,582,379, the disclosures of which are expressly incorporated herein in their entireties by reference. These stirrups may have the disadvantage that when the support arm is upwardly rotated to a point in which the center of gravity of the combination of the leg, the boot, and the support arm is past the axis of rotation of the ratchet mechanism, the support arm spontaneously continues to rotate due to gravity. Accordingly, there is a need in the art for an improved ratchet mechanism for a surgical stirrup which is not susceptible to spontaneous rotation due to gravity.